Objects which are mirrored around a pivot are not exported correctly

[spawnie-no-oni]

Project which causes the issue : https://gitlab.com/JoBarthel/wings
Steps to reproduce :

• select the collection "uv'd wings" and export to Unity FBX, ticking "Active Collection Only".
• import the fbx file into unity.

Expected result :

Actual result :

[EdyJ]

Fixed, thanks for the great repro scene